In all living bodies including human being, organs gradually deteriorate after they are born and as they grow old, and the functions of some of them stop later and the number of the organs of which functions have stopped reaches a certain value or more, resulting in a death. A process in which the functions gradually deteriorate is called aging. Skins are affected directly by their environments, and have an important function to maintain the conditions inside a living body and hence all functions of the skins rarely stop, but the skin is an organ likely to remarkably show signs of aging, such as wrinkles or spots, being of dull color, or being loose, which are marked especially at skin portions exposed to daylight.
As the skin ages, protection of the skin against stimulation, such as oxidation stress, weakens to cause the conditions inside the skin to be bad, thus promoting the aging. Particularly, the skin portion exposed to daylight is always exposed to strong oxidation stress such as ultraviolet radiation, and hence the progress of aging is remarkable in the exposed skin. Such a change of the skin is called photoaging, and in the skin which has suffered from photoaging, the epidermis increases in thickness and the dermis reduces in collagen which is a major constituent of the dermis, to cause deep or large wrinkles on the skin surface, leading to beauty problems.
As a substance having a wrinkle alleviating effect on the wrinkles caused by the photoaging, retinoic acid is used as a prescription drug in the United States, but the retinoic acid has a strong side effect and has a problem from the viewpoint of safety, and hence it has not yet been approved in Japan. Further, as substances for alleviating the wrinkles, retinol (vitamin A) which is believed that it is absorbed by a body and then converted to retinoic acid to exhibit the effect, ascorbic acid (vitamin C) having an antioxidant action and a collagen synthesis promotion effect, and tocopherol (vitamin E) having a strong antioxidant action have been proposed (see, for example, Japanese Unexamined Patent Publication Nos. Hei 7-165567 and Sho 62-164609), but these substances disadvantageously do not have a satisfactory effect. Therefore, a satisfactorily effective and safe substance for diminishing the wrinkles has not yet been developed.
Eugenol is known as a fragrance component of clove which is a kind of spice, and it is known that the eugenol is generally used as an analgesic agent for toothache and others, and further has a blood flow promotion effect or demelanizing effect when applied to a surface topical site, and it is applied to a dermis collagen fascicular reconstruction agent (see, for example, Japanese Unexamined Patent Publication Nos. Hei 9-249549, Hei 6-227959, and 2002-104921). However, the eugenol has problems in that it has a characteristic odor and that it induces sensitization when used in a high concentration (see, for example, Contact Dermatitis, 1992, No. 27, p. 98-104).
The present inventors have found that a glycoside formed from eugenol can solve these problems, and have proposed a hair tonic and a sustained-release aromatic composition for human surface skin (see Japanese Unexamined Patent Publication Nos. Hei 9-40531 and Hei 7-179328), but they have made no studies on a wrinkle alleviating effect of the glycoside of eugenol.